The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
In computer science, an object is a location in memory having a value and referenced by an identifier. Since the introduction of object-oriented programming, an object can refer to a particular instance of a class, and can include multiple fields that have their corresponding values. Relational database management systems may track historical changes to data objects to provide additional information to system users. For example, a salesperson who stores sales opportunity information using a database management system may benefit from accessing the history of the sales opportunity information for a prospective customer, such as changes to the sales opportunity amounts and the sales opportunity scheduled sales dates during the last month. The salesperson contacted a sales lead on January 7th, established a potential sale amount of $1,000 scheduled for the beginning of February, and stored this information using the database management system. On January 14th, the sales lead emailed the salesperson to increase the potential sales amount to $2,000, and the salesperson stored this information. On January 21st, the sales lead called the salesperson to postpone the scheduled sales date to the beginning of March, and the salesperson stored this information. On January 28th, the salesperson called the sales lead, negotiated a revised potential sales amount of $3,000 scheduled for the beginning of April, and stored this information. On January 30th, the salesperson accesses the database management system to determine what were the potential sales amount and the scheduled sales date for this sales opportunity on January 25th when the salesperson had lunch with a friend of the sales lead. The database management system may store the history of changes to data objects by using a name-value pair, such that the database management system may respond to the salesperson's query by retrieving six different name-value pairs stored in data objects before being able to respond that on January 25th the potential sales amount was $2,000 and the scheduled sales date was the beginning of March for this sales opportunity.